"""
Write an algorithm to determine if a number is "happy".

A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not include 1. Those numbers for which this process ends in 1 are happy numbers.

Example: 19 is a happy number

    1**2 + 9**2 = 82
    8**2 + 2**2 = 68
    6**2 + 8**2 = 100
    1**2 + 0**2 + 0**2 = 1

"""


class Solution(object):
    def isHappy(self, n):
        """
        :type n: int
        :rtype: bool
        """
        mem = set()
        while n != 1:
            n = sum([int(i) ** 2 for i in str(n)])
            if n in mem:
                return False
            else:
                mem.add(n)
        else:
            return True


if __name__ == "__main__":
    s = Solution()
    print s.isHappy(19)
